Oxidation inhibitor for insecticides



Patented Jan. 17, 1939 UNITED STATES 2,144,369 OXIDATION INHIBITOR FORINSECTICIDES Dalton B. Faloon, Beacon, N. Y., assignor to Hammond Paint& Chemical 00., Inc., Beacon, N. Y., a corporation of New York NoDrawing. Application May 14, 1938, Serial No. 208,055

3 Claims. (Cl. 167- 24) s The present application and invention coveredthereby is a continuation-in-part of my copendlug-application Serial No,695,001, filed October 24, 1933.

5 This invention relates, generally, to insecticides and the inventionhas reference, more particularly, to means for preventing the more orless rapid deterioration of insecticides such as pyrethrum and rotenonein use.

,10 Organic insecticides heretofore produced such as ,pyrethrum androtenone have been found to lose their toxic properties more or lessrapidly so that ofttimes after these substances have been stored orunused for atlme their value as insecticides is greatly reduced andcannot produce the results desired.

This is particularly true of insecticide solutions, and it has beenknown that the presence of alkaline materials, such as sodium andpotassium salts in the insecticide solution or the presence of moisturealso greatly accelerates the rate of deterioration. Also, exposure tothe air and sunlight serve to rapidly lower the toxic value of such .35is the main cause of loss of toxicity in insecticides and that the rateof deterioration varies in proportion to the ability of oxygen to comein contact with the individual units of the toxic substances. I v

The principal object of the present invention is to provide a method forpreventing the rapid oxidation and consequent deterioration of organicinsecticides. I v other object oi this invention. is to provide 5. meanswhich "hen -added to organic insecticides will enable such insecticidesto be stored for relatively long periods-without appreciable loss oftoxicity."

Still another object 01' this invention is to provide means which maybe, readily dispersed throughout the mass of an insecticide, the saidmeans serving to blanket and protect the toxic ingredients otgtheinsecticide against oxidation, thereby enabling such protectedinsecticide to be 1;, left exposed to light and air without appreciablecatalysts for producing uniform results.

deterioration of the toxic character of the same.

These objects are achieved by the following invention, that enablesorganic insecticides which possess the objections here underconsideration, to be stabilized and protected from deterioration 5without altering their toxic properties or field of use, by additions ofoxidation inhibitors and by controlling the character and magnitude ofsuch additions so that the desired protection of the insecticidecomposition is obtained for unlimited in periods. In particular, it hasbeen found that relatively small amounts of aromatic amines andderivatives are especially adaptable for use as oxidation inhibitors forthese purposes.

In carrying out the present invention, extract is derivatives from toxicorganic substances are prepared according to the known methods of theart using various solvents and adding the oxidation inhibitors ornegative catalysts of this invention. It was found that various solventsre- 20 quired greatly varying percentages of negative Also, the relativesolubility of a particular oxidation inhibitor in any particular solventwas found to be highly important in determining the percentage ofinhibitor to be used. To be effective, it is essential that theoxidation inhibitor be completely dispersed throughout the insecticidecomposition and that no separation occurs during storage aftermanufacture. Some solvents permit the' use of certain types ofinhibitors which are not readily dispersed in other types of solvents. Ihave found that the more completely the oxidation inhibitor is dispersedin the vehicle the more effective the inhibitor becomes. a

Y The following products are specific examples of some or the aromaticamines and derivatives which have been found-satisfactory as oxidationinhibitors or negative catalysts in the present process; Hexamethylenetetramine, diphenyl- 40 amine, benzidine and para-amino'phenol. 4

The quantity of any particular oxidation inhibitor used-in anyparticular insecticide corn position is dependent upon variable, factorsand for this reason no hard and fast rule can be laid down. Not only thenature of the insecticide used but also the nature 01 the solvent orvehicle employedwith the insecticide play an important part indeterminingithe quantity or proportion of oxidation inhibitor necessaryto protect the so insecticide against deterioration. The varioussolvents that may be used as a vehicle such as alcohoLLacetQne. carbontetrachloride, ethylene dichloride, neutral petroleum oil, kerosene,gasolene, mineral spirits, etc.,'or or two or more of these solventsvary in their respective abilities to disperse the inhibitor or negativecatalyst used in any instance that diflerent proportions of anyparticular catalyst are necessary with different vehicles. Acetone, forexample, which may contain some moisture requires more negative catalystto inhibit oxidation than a vehicle of alcohol. Vehicles containingsulphonated oils or moisture require larger proportions of inhibitorsthan those not having these ingredients therein.

In general, I have found that the quantity of the negative catalyst oroxidation inhibitor necessary to overcome premature oxidation ordeterioration of the toxic principles of organic insecticides will beless than 1% by weight on the basis of total composition. In some casesquantities of inhibitors as low as .05% or even lower by weight of thetotal composition have appreciable efl'ects, while in other cases .6%and .8% aremore effective. In rare combinations of vehicles, quantitiesof inhibitors in excess of 1% and up to the amount of 1.5% by weight ofthe total combination have been required to obtain the desired results.It is understood however, that I do not wish to limit myself entirely topercentages below 1.5%, because greater percentages of the inhibitorsmay be used, although the additional benefits or protection derived bythe use of larger percentages than 1.5% are generally substantiallynegligible.

Owing to the great number and diversity of insecticide compositionscomprising toxic substances such as rotenone, pyrethrum, derris, etc.,and a great variety of vehicles and vehicle combinations, whichcompositions I have found to be protected against oxidation by thepreviously mentioned inhibitors, it is impracticable to list theingredientsof all such compositions. However, a representative'exampleof insecticide composition is given below, the ingredients listed beingmixed together with stirring in the percentages given by weight:

Percent by Composition weight Pyrethrum 2. 5 Para-nminnnhnnnl 8 A lonhnl90. 00 Aceto 6.

Having thus described my invention, what I claim and desire to protectby Letters Patent is:

1. An insecticide comprising an easily oxidizable organic vegetabletoxic material of the group consisting of pyrethrum and rotenone and anaromatic amine of the group consisting of diphenylamine and benzidine.

2. An insecticide comprising pyrethrum and.

diphenylamine to stabilize the same.

3. An insecticide comprising rotenone and diphenylamine to stabilize thesame.

DALTON B. FALCON.

